Angelfish fins don't really tear that easy from what I've seen... The only times I've seen Angels with ripped fins is when another fish is picking at them or they have a disease like fin rot. I don't see that often though.
@Ebirah766 Might as well put them in a bare tank if it's "better safe than sorry." Anything with animals involves risk of some kind... especially if the enclosure is naturalistic. We can do our best to prevent accidents and injuries, but sometimes things just happen. The animals are much happier given the risk anyway... a gibbon that can't climb and swing or an aardvark that can't dig are not happy at all... that's why the zoos of today do better with breeding and longevity... a varied, enriched exhibit is far better for the animals than a bare one.
Back to the angelfish, you know the fins do heal if they get torn right? I've personally had fish heal with no visible sign the fin was ever torn (I even had one regrow a section of its tail that had apparently been bitten off before I purchased it).
